The history of the United States from 1865 until 1918 covers the Reconstruction Era, the Gilded Age, and the Progressive Era, and includes the rise of industrialization and the resulting surge of immigration in the United States. This article focuses on political, economic, and diplomatic history.

This period of rapid economic growth and soaring prosperity in the North and the West (but not in the South) saw the U.S. become the world's dominant economic, industrial, and agricultural power. The average annual income (after inflation) of non-farm workers grew by 75% from 1865 to 1900, and then grew another 33% by 1918.[1]

With a decisive victory in 1865 over Southern secessionists in the Civil War, the United States became a united and powerful nation with a strong national government. Reconstruction brought the end of legalized slavery plus citizenship for the former slaves, but their new-found political power was rolled back within a decade, and they became second-class citizens under a "Jim Crow" system of deeply pervasive segregation that would stand for the next 80–90 years. Politically, during the Third Party System and Fourth Party System the nation was mostly dominated by Republicans (except for two Democratic presidents). After 1900 and the assassination of President William McKinley, the Progressive Era brought political, business, and social reforms (e.g., new roles for and government expansion of education, higher status for women, a curtailment of corporate excesses, and modernization of many areas of government and society). The Progressives worked through new middle-class organizations to fight against the corruption and behind-the-scenes power of entrenched, state political party organizations and big-city "machines". They demanded—and won—women's right to vote, and the nationwide prohibition of alcohol 1920-1933.

In an unprecedented wave of European immigration, 27.5 million new arrivals between 1865 and 1918[2] provided the labor base necessary for the expansion of industry and agriculture, as well as the population base for most of fast-growing urban America.

There were also two very important wars. The U.S. easily defeated Spain in 1898, which unexpectedly brought a small empire. Cuba quickly was given independence, as well as the Philippines (in 1946). Puerto Rico (and some smaller islands) became permanent U.S. possessions, as did Alaska (added by purchase in 1867). The independent Republic of Hawaii voluntarily joined the U.S. as a territory in 1898.

The United States tried and failed to broker a peace settlement for World War I, then entered the war after Germany launched a submarine campaign against U.S. merchant ships that were supplying Germany's enemy countries. The publicly stated goals were to uphold American honor, crush German militarism, and reshape the postwar world. After a slow mobilization, the U.S. helped bring about a decisive Allied Forces victory by supplying badly needed financing, food, and millions of fresh and eager soldiers.

Reconstruction Era

Reconstruction gave black farmers, businessmen and soldiers the right to vote for the first time in 1867, as celebrated by Harper's Weekly on its front cover, Nov. 16, 1867.[3]

Reconstruction was the period from 1863 to 1877, in which the federal government temporarily took control—one by one—of the Southern states of the Confederacy. Before his assassination in April 1865, President Abraham Lincoln had announced moderate plans for reconstruction to re-integrate the former Confederates as fast as possible. Lincoln set up the Freedmen's Bureau in March 1865, to aid former slaves in finding education, health care, and employment. The final abolition of slavery was achieved by the Thirteenth Amendment, ratified in December 1865.[4] However, Lincoln was opposed by the Radical Republicans within his own party who feared that the former Confederates would never truly give up on slavery and Confederate nationalism, and would always try to reinstate them behind-the-scenes. As a result, the Radical Republicans tried to impose legal restrictions that would strip most ex-rebels' rights to vote and hold elected office. The Radicals were opposed by Lincoln's Vice President and successor, Tennessee Democrat Andrew Johnson. However, the Radicals won the critical elections of 1866, winning enough seats in Congress to override President Johnson's vetoes of such legislation. They even successfully impeached President Johnson (in the House of Representatives), and almost removed him from office (in the Senate) in 1868. Meanwhile, they gave the South's "freedmen" new constitutional and federal legal protections.

The Radicals' reconstruction plans took effect in 1867 under the supervision of the U.S. Army, allowing a Republican coalition of Freedmen, Scalawags (sympathetic local whites), and Carpetbaggers (recent arrivals from the North), to take control of Southern state governments. They ratified the Fourteenth Amendment, giving enormous new powers to the federal courts to deal with justice at the state level. These state governments borrowed heavily to build railroads and public schools, increasing taxation rates. The backlash of increasingly fierce opposition to these policies drove most of the Scalawags out of the Republican Party and into the Democratic Party. President Ulysses S. Grant enforced civil rights protections for African-Americans that were being challenged in South Carolina, Mississippi, and Louisiana. The Fifteenth Amendment was ratified in 1870 giving African-Americans the right to vote in American elections.

U.S. Representative Stevens was one of the major policymakers regarding Reconstruction, and obtained a House vote of impeachment against President Andrew Johnson. Hans Trefousse, his leading biographer, concludes that Stevens "was one of the most influential representatives ever to serve in Congress. [He dominated] the House with his wit, knowledge of parliamentary law, and sheer willpower, even though he was often unable to prevail."[5]

Reconstruction ended at different times in each state, the last in 1877, when Republican Rutherford B. Hayes won the contentious presidential election of 1876 over his opponent, Samuel J. Tilden. To deal with disputed electoral votes, Congress set up an Electoral Commission. It awarded the disputed votes to Hayes. The white South accepted the "Compromise of 1877" knowing that Hayes proposed to end Army control over the remaining three state governments in Republican hands. White Northerners accepted that the Civil War was over and that Southern whites posed no threat to the nation.[6][7]

The end of Reconstruction marked the end of the brief period of civil rights and civil liberties for African Americans in the South, where most lived. Reconstruction caused permanent resentment, distrust, and cynicism among white Southerners toward the federal government, and helped create the "Solid South," which typically voted for the (then-)socially conservative Democrats for all local, state, and national offices. White supremacists created a segregated society through "Jim Crow Laws" that made blacks second-class citizens with very little political power or public voice.[8] The white elites (called the "Redeemers"—the southern wing of the "Bourbon Democrats") were in firm political and economic control of the south until the rise of the Populist movement in the 1890s. Local law enforcement was weak in rural areas, allowing outraged mobs to use lynching to redress alleged-but-often-unproven crimes charged to blacks.[9]

Historians' interpretations of the Radical Republicans have dramatically shifted over the years, from the pre-1950 view of them as tools of big business motivated by partisanship and hatred of the white South, to the perspective of the neoabolitionists of the 1950s and afterwards, who applauded their efforts to give equal rights to the freed slaves.[10]

In the South itself the interpretation of the tumultuous 1860s differed sharply by race. Americans often interpreted great events in religious terms. Historian Wilson Fallin contrasts the interpretation of Civil War and Reconstruction in white versus black using Baptist sermons in Alabama. White preachers expressed the view that:

God had chastised them and given them a special mission – to maintain orthodoxy, strict Biblicism, personal piety, and traditional race relations. Slavery, they insisted, had not been sinful. Rather, emancipation was a historical tragedy and the end of Reconstruction was a clear sign of God's favor.

God's gift of freedom. They appreciated opportunities to exercise their independence, to worship in their own way, to affirm their worth and dignity, and to proclaim the fatherhood of God and the brotherhood of man. Most of all, they could form their own churches, associations, and conventions. These institutions offered self-help and racial uplift, and provided places where the gospel of liberation could be proclaimed. As a result, black preachers continued to insist that God would protect and help them; God would be their rock in a stormy land.[11]

Historians in the 21st century typically consider Reconstruction to be a failure, but they "disagree on what caused Reconstruction to fail, focusing on whether it went too far, too fast or did not go far enough."[12]

However, historian Mark Summers in 2014 sees a positive outcome:

if we see Reconstruction's purpose as making sure that the main goals of the war would be filled, of a Union held together forever, of a North and South able to work together, of slavery extirpated, and sectional rivalries confined, of a permanent banishment of the fear of vaunting appeals to state sovereignty, backed by armed force, then Reconstruction looks like what in that respect it was, a lasting and unappreciated success.[13]